0.0
NA
CVE-2024-39276
Linux Kernel Ext4 MBCache Reference Count Leak
Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

INFO

Published Date :

June 25, 2024, 3:15 p.m.

Last Modified :

June 25, 2024, 6:50 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

Exploitability Score :

Affected Products

The following products are affected by CVE-2024-39276 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2024-39276.

URL Resource
https://git.kernel.org/stable/c/0c0b4a49d3e7f49690a6827a41faeffad5df7e21
https://git.kernel.org/stable/c/681ff9a09accd8a4379f8bd30b7a1641ee19bb3e
https://git.kernel.org/stable/c/76dc776153a47372719d664e0fc50d6355791abb
https://git.kernel.org/stable/c/896a7e7d0d555ad8b2b46af0c2fa7de7467f9483
https://git.kernel.org/stable/c/9ad75e78747b5a50dc5a52f0f8e92e920a653f16
https://git.kernel.org/stable/c/a95df6f04f2c37291adf26a74205cde0314d4577
https://git.kernel.org/stable/c/b37c0edef4e66fb21a2fbc211471195a383e5ab8
https://git.kernel.org/stable/c/e941b712e758f615d311946bf98216e79145ccd9

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2024-39276 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2024-39276 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 25, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.
    Added Reference kernel.org https://git.kernel.org/stable/c/9ad75e78747b5a50dc5a52f0f8e92e920a653f16 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/896a7e7d0d555ad8b2b46af0c2fa7de7467f9483 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/76dc776153a47372719d664e0fc50d6355791abb [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/681ff9a09accd8a4379f8bd30b7a1641ee19bb3e [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/e941b712e758f615d311946bf98216e79145ccd9 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/a95df6f04f2c37291adf26a74205cde0314d4577 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/b37c0edef4e66fb21a2fbc211471195a383e5ab8 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/0c0b4a49d3e7f49690a6827a41faeffad5df7e21 [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2024-39276 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2024-39276 weaknesses.

NONE - Vulnerability Scoring System
: